1. Field
Exemplary embodiments relate to a method for fabricating a semiconductor device, and more particularly to a method for fabricating a semiconductor device including a variable resistance layer which has resistance that is changed in accordance with a voltage or current applied thereto and can perform switching between at least two different resistance states.
2. Description of the Related Art
A variable resistance memory device is a device which stores data using the characteristics that the resistance of the memory device is changed in accordance with an external stimulus and the memory device can perform switching between at least two different resistance states, and may include a ReRAM (Resistive Random Access Memory), a PCRAM (Phase Change RAM), a STT-RAM (Spin Transfer Torque-RAM), and the like. In particular, since the variable resistance memory device can be formed with a simple structure and has superior characteristics, such as non-volatility, extensive researches for the variable resistance memory device have been made.
ReRAM has a structure which includes a variable resistance layer made of a variable resistance material, e.g., Perovskite material or a transition metal oxide and electrodes disposed over upper and lower portions of the variable resistance layer. In accordance with the voltage applied to the electrodes, a current path in the form of a filament is generated or disappears in the variable resistance layer. Accordingly, the variable resistance layer is at a low resistance state when the current path in form of a filament is generated, and is at a high resistance state when the current path in the form of a filament becomes disappeared.